(i) Field to which the invention relates
The present invention relates to an eccentric plate grinder having a housing, a driving shaft bearinged in the housing, an eccentric supported on one end of the driving shaft, and a grinding plate powered by way of the eccentric.
(ii) The prior art
As presently marketed, such plate grinders have a grinding plate which may be freely turned on the eccentric of the driving shaft so that the center point of the grinding plate is moved in a circle about the axis of the driving shaft. Turning of the grinding plate about its own axis in addition is produced by a friction clutch in the bearing by unsymmetrical loading of the grinding plate when used for grinding operations.
In the case of such prior art eccentric plate grinding machines, the grains of the abrasive paper are moved in circles as well so that each grain will be kept within the groove produced by it on moving over the workface so that there is still room for design development to get a better grinding effect (in addition to simply increasing the grinding speed, which is responsible for troubles in connection with drawing off the dust produced by the abrasive process).